/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2026 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Class
    Foam::functionObjects::generateZone

Description
    Generates, registers and optionally writes the \c zoneSet generated by
    a \c zoneGenerator.

Usage
    \table
        Property     | Description                 | Required    | Default value
        type         | type name: generateZone     | yes         |
        zone         | zoneGenerator specification | yes         |
    \endtable

    Example of a functionObjects::generateZone which creates a \c cellZone named
    \c kZone of the cells in which the value of the turbulent kinetic energy is
    within the highest 10% and then functionObjects::volFieldValue
    is used to average the velocity within this zone:
    \verbatim
    kZone
    {
        type generateZone;

        libs        ("libutilityFunctionObjects.so");

        executeControl  writeTime;
        writeControl    writeTime;

        zone
        {
            type coded;

            code
            #{
                // Lookup field from the objectRegistry, e.g. k
                const volScalarField& k =
                    mesh().lookupObject<volScalarField>("k");

                // Calculate the minimum and maximum k values
                const scalar mink = min(k).value();
                const scalar maxk = max(k).value();

                // Fraction of the range of k
                const scalar f = 0.1;

                // Lowest k in selection
                const scalar lowk = f*mink + (1.0 - f)*maxk;

                cellIndices = selectIndices
                (
                    k,
                    [&](const scalar k)
                    {
                        return k > lowk;
                    }
                );
            #};
        }
    }

    UAverage
    {
        type            volFieldValue;

        libs            ("libfieldFunctionObjects.so");

        executeControl  writeTime;
        writeControl    writeTime;

        writeFields     no;

        cellZone        kZone;

        operation       volAverage;

        fields          (U);
    }
    \endverbatim

See also
    Foam::functionObject

SourceFiles
    generateZone.C

\*---------------------------------------------------------------------------*/

#ifndef generateZone_functionObject_H
#define generateZone_functionObject_H

#include "fvMeshFunctionObject.H"
#include "zoneGenerator.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{
namespace functionObjects
{

/*---------------------------------------------------------------------------*\
                   Class generateZone Declaration
\*---------------------------------------------------------------------------*/

class generateZone
:
    public fvMeshFunctionObject
{
    // Private Data

        //- Run-time selected zoneGenerator
        autoPtr<zoneGenerator> zg_;


public:

    //- Runtime type information
    TypeName("generateZone");


    // Constructors

        //- Construct from Time and dictionary
        generateZone
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );

        //- Disallow default bitwise copy construction
        generateZone(const generateZone&) = delete;


    //- Destructor
    virtual ~generateZone();


    // Member Functions

        //- Return the list of fields required
        virtual wordList fields() const
        {
            return wordList::null();
        }

        //- Remove the registered objects
        virtual bool execute();

        //- Do nothing
        virtual bool write();


    // Member Operators

        //- Disallow default bitwise assignment
        void operator=(const generateZone&) = delete;
};


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace functionObjects
} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //